Just to thank Jeffery for enlightining me. It seems that I already knew about photopolymers - but had never heard them called that. In fact about 50 years ago I actually used the system to etch brass, using gelatin, dichromate and a little prussian blue to coat the brass, put a negative over it, exposed it to sunlight, washed off with hot water, then used nitric acid to do the etch - it worked (after a style!) It is exactly the same system to make electronic circuit boards but one uses ferric chloride to do the etching. And I said I didn’t know!.. But I what threw me was the idea of using it for 3D work.
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/ / John Burgess
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/ /__ johnb@ts.co.nz
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